As communication technology advances, evolution of 3G mobile communication systems is about to reach their fourth generation (4G). Such a 4G mobile communication system enables portable terminals capable of using mobile communication systems to be based on IP (Internet Protocol) in communication, and implement fast upload and download speeds.
Evolution for reaching the 4G mobile communication system contributes to sending/receiving user data even faster. On the contrary, portable terminals are expected to consume more power to cause the available time of portable terminals to be reduced.
Accordingly, there is a need for developing a method for improving battery life on portable terminals in line with emerging 4G mobile communication systems.
The exemplary Green-T(echnology) of EUREKA project has studied the technology for minimizing power consumed by the 4G portable terminals by adopting the heterogeneous radio access technology in order to overcome the aforementioned energy trap thereof.
In particular, the Green-T project aims to develop a method for implementing data communication by using a neighboring short-range wireless communication system if much transmission power is required for sending/receiving data to/from a base station because terminals are far away from the base station.
For example, FIG. 1 shows an exemplary system block using a wireless LAN or wireless PAN (Personal Area Network) for a portable terminal with battery limitation in short-range wireless communication with other portable terminal while the other portable terminal uses 4G mobile communication for relay to a base station.
The other portable terminal may be a portable terminal free from power consumption compared with the portable terminal in the battery limitation.
FIG. 2 shows a system block for sending/receiving data to/from a portable terminal by using a short-range wireless communication system, for example, a wireless LAN or high-speed wireless PAN, not 4G mobile communications.
The aforementioned FIGS. 1 and 2 illustrate reducing power consumption by utilizing a neighboring portable terminal or neighboring short-range wireless communication system while adopting short-range wireless communication, not direct wireless communication through a base station.
Portable terminals of which the battery levels drop below a certain level and which do not consume enough power or have battery limitation utilize short-range wireless communication systems, for example, a wireless LAN or wireless PAN in place of using a base station in order to reduce power consumption, as shown in FIGS. 1 and 2. In this case, however, it is also necessary to discover a device for sending or receiving data by wire or wireless to/from a base station or a mobile communication control station for managing or working as the base station in place of access to the base station of a portable terminal in a short-range wireless communication system.
Meanwhile, the aforementioned device generally broadcasts data (for example, discovery data) providing information required for a portable terminal to be connected with a short-range wireless communication system.
Therefore, it is essential that a portable terminal in a battery shortage status supplies power to a hardware module corresponding to a wireless LAN or wireless PAN included in the portable terminal in order to receive broadcast radio data packets. Continuous power supply for receiving the broadcast radio data packets results in consuming more power.
In addition, broadcast radio data packets may be lost or not normally received due to collision with broadcast radio data packets of other devices which use a short-range wireless communication system. Therefore, the portable terminal in a battery shortage status may not normally receive the broadcast radio data packets, and consume more power for discovering a short-range wireless communication system.
As a result, there is a need for a short-range wireless communication access device, a portable terminal for discovering a short-range wireless communication access device and a short-range wireless communication system, so that the portable terminal can reduce power consumption required to access the short-range wireless communication system and to use the short-range wireless communication system and also receive radio data packets for the discovery data through shared wireless media even more safely and with more probability.